The present invention relates to material handling conveyor systems, and more particularly to a pallet for conveying an article along a conveyor path and turning the article carried thereon at various work stations positioned there along.
Various rotatable pallets and workpiece fixtures are known.
For example, U.S. Pat. No. 2,775,333 teaches a pallet which is guided along a path defined by casters affixed to a guide rail. The pallet is pulled along the guide rail by a chain. Gates or movable channel sections are located next to the guide rails to engage the edge of the pallet as it moves therepast. As the gates are pivoted, they cause the pallets to rotate as the pallets are moving along the path.
It is also known from U.S. Pat. No. 3,785,853 to have a moving plate conveyor upon which a workpiece rests with two endless workpiece contact belt systems located opposite each other to opposite longitudinal sides of the moving plate conveyor so that the endless belts contact opposite sides of the workpiece as the workpiece passes therebetween on the plate conveyor. The endless belts are operated at different linear speeds so as to turn the workpiece passing therebetween.
In U.S. Pat. No. 3,938,653 it is known to have a workpiece carrying pallet which is moved along a conveying path and is caused to rotate as it advances or moves there along. The conveyor includes a center endless belt which has upwardly projecting pins which are received in a centered aperture in the bottom of the pallet. Two spaced apart drive belts run parallel to the endless belt on either side of a center belt and functionally contact the bottom side of the pallet to move the pallet along the conveyor path. One drive belt is driven at a higher linear speed than the other drive belt which causes the pallet to rotate about the pin of the center endless belt as the pallet is moved along the conveyor path.